A 27-year-old woman experienced pruritus, eye and throat irritation, hoarseness, shortness of breath, and fatigue within half and hour of exposure to carbonless copy paper. On two separate occasions, she was purposely challenged in a controlled-blinded fashion with portions of the carbonless copy paper. This resulted on both occasions in contact urticaria of the hand that held the paper and changes in pulmonary function flow-volume loops characteristic of upper airway obstruction. To determine if alterations in prostaglandin (PG) metabolism might explain these findings, plasma PGF2 alpha and thromboxane B2 (both capable of causing these symptoms) were measured before and during the second exposure period. Both PGF2 alpha and thromboxane B2 increased substantially. We conclude that the cutaneous and respiratory symptoms induced by carbonless copy paper were probably related to PG release.